Unicompartmental knee arthroplasty in octogenarians: An analysis of 1,466 patients with 2-year follow-up

Introduction

Unicompartmental knee arthroplasty (UKA) has been shown to improve pain and function in appropriately selected patients. Limited data exists regarding outcomes and complication rates following UKA among octogenarians.

Methods

The PearlDiver Mariner database was queried for patients undergoing primary UKA between 2010–2022. Patients < 80 years old were matched 4:1 to the octogenarian cohort (≥80 years old) by sex, year, Elixhauser Comorbidity Index (ECI), tobacco use, obesity, and diabetes. A total of 1,334 octogenarians and 5,313 controls were included in our analysis. Multivariate logistic regression was utilized to compare medical complications at 90-days post-operatively and surgical complications at 1- and 2-years post-operatively. Our regression analysis controlled for sex, ECI, tobacco use, obesity, and diabetes.

Results

Octogenarians had an increased risk of acute kidney injury (OR: 2.306, 95% CI: 1.393–3.749; p < 0.001), pneumonia (OR: 2.367, 95% CI: 1.301–4.189; p = 0.003), UTI (OR: 1.846, 95% CI: 1.304–2.583; p < 0.001), ED visits (OR: 2.229, 95% CI: 1.586–3.105; p < 0.001), and any complication (OR: 1.575, 95% CI: 1.304–1.895; p < 0.001) at 90-days post-operatively. Octogenarians had lower odds of all-cause revision at 2-years (OR: 0.607, 95% CI: 0.382–0.923; p = 0.026). No differences were demonstrated between cohorts in rates of PJI (OR: 0.832, 95% CI: 0.334–1.796; p = 0.664), periprosthetic fracture (OR: 0.516, 95% CI: 0.120–1.520; p = 0.289), or aseptic loosening (OR: 0.285, 95% CI: 0.045–1.203; p = 0.088) at 2-years.

Discussion

These findings suggest that despite an increased risk of certain medical complications within the acute post-operative period, octogenarians undergoing UKA experienced similar rates of surgical complications to younger matched controls at 2-year follow-up.